Heart Failure, often called congestive heart failure, is a condition in which the heart can no longer pump sufficient blood to the rest of the body. Heart failure is a major health problem in the U.S. with hundreds of thousands of cases diagnosed each year. There are a variety of causes for heart failure. The most common cause is coronary artery disease, which is a narrowing of the small blood vessels that supply blood and oxygen to the heart. Other causes of heart failure include congenital heart disease, heart attacks, heart valve diseases and abnormal heart rhythms (arrhythmias).
A variety of surgeries and devices have been developed to treat patients with heart failure, including coronary bypass surgery, angioplasty, heart valve surgery, addition of a pacemaker, or installation of a defibrillator. When treatments no longer work, a patient is said to be in end-stage heart failure. For patients in end-stage heart failure, a heart transplant is often the only possible treatment option. Unfortunately, there is a serious shortage of donors. The annual number of donor hearts remains around 2,000. However, the patients who are qualified to receive and need donor hearts is estimated to be about 16,500. To compensate for this lack of donor hearts, mechanical circulation support systems have been intensively studied and developed. Such mechanical circulation support systems include artificial hearts and ventricular assist devices.
A ventricular assist device (VAD) is a mechanical pump that helps a ventricle to pump blood throughout the body. The VAD pumps the blood from a weakened or diseased ventricle to the aorta or a pulmonary artery. The components of a VAD vary according to the specific device used. In general, a VAD includes a pump, connections to and from the heart, a control system and an energy supply. A general representation of a ventricular assist device is presented in FIG. 1. Referring now to FIG. 1, a patient 2 is shown with an implanted VAD 4 in the body of the patient 2. The patient's heart 6 includes the left ventricle 8 which is attached to a ventricle tube 10 which enters the left ventricle 8. The ventricle tube 10 is attached to a pump 12. A variety of pumps are used in VADs, including rotary and axial flow pumps. The pump 12 pumps blood from the left ventricle 8 into a pump exit tube 14 which delivers the blood to the aorta 16. The pump 12 has a control unit wire 18 which is attached to the pump 12 and which exits the patient's body 2 and is attached to a control unit 20. The control unit 20 controls the action of the pump 12 and is attached to a power unit wire 22 which attaches to a power unit 24 which powers the pump 12. A power unit 24 may be battery charged or may plug into a power source such as a wall outlet. A variety of means are available to carry the power unit 24, such as a sling 26. In some instances a VAD is used to keep the patient alive until a donor heart is available. Such use is referred to as a “bridge to transplant.” In “destination therapy” a VAD is used in place of a heart transplant to provide a long-term solution for patients that are not eligible for a heart transplant.
There are situations where a patient needs a VAD, but the ventricle in need of the VAD is diseased or otherwise damaged in a way that makes attachment of the VAD to the ventricle difficult or impossible. The present invention is directed to sleeve adapter and methods for connecting a VAD to a damaged or diseased ventricle thereby greatly expanding the number of patients able to receive a VAD.